We propose to establish an image analysis facility at the University of Pennsylvania School of Medicine. The specific aim of the facility will be to extend the utility and limited analytical power of the technique of high resolution, two-dimensional gel electrophoresis. The instrumentation needs for the computer-linked analysis of two-dimensional gels of radiolabeled polypeptides is presented. Data acquisition is first obtained by digitization of an autoradiographic or fluorographic image using an Optronics P-1000 rotating-drum scanner, followed by procedures for spot detection, quantitation and gel comparisons. A group of major users, whose studies make extensive use of two-dimensional gel electrophoresis has been identified and individual research proposals outlined. The areas of study are broadly representative of biomedical research in the School of Medicine, covering aspects of developmental biology, cellular differentiation, viral transformation, and hormone action at the molecular level. A plan for the management, resource responsibilities, time-sharing, and day-to-day operation of the facility is presented. An Advisory Committee has been assembled, and its administrative role identified.